Drug abuse among women is a major societal health problem that has been under-investigated until recently. Current advances show statistically significant differences between males and females in all phases of drug exposure. Clinical studies demonstrate that females are more susceptible to relapse compared to males and that this relapse is accompanied by negative emotions including anxiety. Physiological fluctuations during drug exposure and following abstinence from the drug may contribute to female sensitivity to the anxiogenic effects of cocaine. The guiding hypothesis of this proposal is that female hormones, via actions on dopamine and opioid systems, may contribute to the increase in anxiety during cocaine withdrawal. These studies will seek to examine anxiety-like behaviors in female rats during abstinence from chronic cocaine exposure and correlate these with hormonal fluctuations. The contribution of 6-opioid receptors in cocaine-induced anxiety will also be determined.